The present invention relates to a particle separator, and particularly to a particle separator for. a gas turbine engine. More particularly, the present invention relates to a particle separator configured to separate particles from a stream of air entering an air intake of the engine.
Particle separators are provided to separate undesirable particles from a stream of air entering or flowing through a gas turbine engine. Such particles can adversely affect the internal working components of the engine. Some engines are intended to operate in particulate-laden environments, such as in dusty and sandy locations. In these types of environments, a particle separator capable of separating fine particles (e.g., particles having a diameter of 2.5 microns) from the stream of air entering the engine could help protect the engine.
According to the present disclosure, a particle separator for the air intake of a gas turbine engine includes a housing that defines an axis and is adapted to be coupled to the engine. The housing further defines an annular first flow passage, an annular first opening, and an annular second flow passage positioned in fluid communication with the first flow passage through the first opening. The first and second flow passages and the first opening are positioned concentrically about the axis.
The particle separator further includes a plurality of nozzle vanes coupled to the housing and spaced circumferentially about the axis in the first flow passage. The nozzle vanes are configured and positioned to impart a velocity to a stream of air flowing through the first flow passage and a different velocity to particles entrained in the stream of air as the stream of air flows past the nozzle vanes. The particle separator also includes a rotor including a plurality of blades positioned in the first flow passage and a blade support. The blades are coupled to the blade support for rotation of the blades about the axis in response to the stream of air flowing past the blades downstream of the first vanes. This allows the blades to deflect particles entrained in the stream of air into the second flow passage through the first opening so that the stream of air can enter the engine from the first flow passage free of the particles removed therefrom.
In illustrative embodiments, the particle separator includes an inlet and an outlet positioned radially inwardly from the inlet. The nozzle vanes, the blades, and the first opening are positioned generally radially inwardly from the inlet and generally radially outwardly from the outlet. In addition, the nozzle vanes and at least a portion of the first opening are positioned generally radially outwardly from the blades. This is so that the stream of air flows radially inwardly while the particles migrate radially outwardly through the first opening into the second flow passage in response to the particles impacting the rotating blades to achieve particle separation.
In other illustrative embodiments, the particle separator includes a row of de-swirl vanes coupled to the housing and positioned downstream of the nozzle vanes and the blades. The de-swirl vanes are configured to remove the swirling motion of the airstream induced by the nozzle vanes to limit the pressure drop across the particle separator.
In yet other illustrative embodiments, the particle separator includes an inertial particle separator section positioned upstream of the row of nozzle vanes, the rotor, and the row of de-swirl vanes. The nozzle vanes, the rotor, and the row of deswirl vanes may be thought of as being components of a dynamic particle separator section of the particle separator. The inertial particle separator section is configured to separate coarse particles from the airstream while the dynamic particle separator section is configured to separate fine particles from the airstream. Removal of coarse particles upstream from the dynamic particle separator section can help lengthen the useful life of the blades by avoiding erosion of the blade tips, or leading edges, that could be caused by coarse particles impacting the blade tips.